1. Field of the Invention
The invention relates to a non-spurting dispensing closure and more particularly to such a closure comprising a shell and a tip with an elevating and lowering mechanism apart from the shell chimney and stop means whereby the tip may be shifted between positively defined open and closed positions by limited twisting thereof with respect to the shell.
2. Description of the Prior Art
The dispensing closure of the present invention, comprising a shell and a tip, is applicable to any appropriate type of container having a neck or finish with which the shell may be engaged. The term "container," as used herein and in the claims, is to be interpreted as being inclusive of glass or plastic bottles, metallic cans and the like. While the shell of the dispensing closure of the present invention will be illustrated, for purposes of an exemplary showing, as being internally threaded for a threaded engagement with the neck or finish of the container, other methods of engagement between the shell and the neck or finish of the container may be employed without departing from the spirit of the present invention.
Prior art workers have devised many types of dispensing closures comprising a shell having an upstanding, substantially cylindrical chimney and a tip mounted on the chimney and shiftable with respect thereto between an open and a closed position. For example, a dispensing closure with a tip having a push-pull relationship with the chimney of the shell has found great utility in connection with the dispensing of many fluids. This is true because such closures are relatively inexpensive to manufacture, reliable, and easy to operate. The captive nature of the tip with respect to the shell eliminates the requirement of a separate cap means.
Prior art workers have also devised "twist-open" dispensing closures having a tip member threaded onto the chimney of the shell. Such twist-open dispensing closures, however, due to the necessity for full threads thereon, generally are expensive to mold in that the dye member forming the threads must be unscrewed from the molded part. Such closures are also less convenient for the user than push-pull type closures because of the large amount of twist necessary to unscrew the tip member sufficiently to open the closure.
Push-pull closures have been highly satisfactory for dispensing numerous fluid substances such as, by way of example only and without limitation, liquid cleaning preparations. There have recently been developed, however, abrasive, liquid cleaning preparations which are thixotropic, having very high viscosity at low shear rates and which require that they be thoroughly mixed, as by shaking, immediately before use. Such cleaning preparations are disclosed, for example, in U.S. patent application Ser. No. 415,033, entitled LIQUID ABRASIVE CLEANER WITH HYPOCHLORITE BLEACH, filed Nov. 12, 1973 by W. L. Hartman, now U.S. Pat. No. 4,005,027 and assigned to the Procter and Gamble Company. When a push-pull closure was attempted to be utilized in connection with this thixotropic cleaner, following shaking thereof, it was found that a substantial quantity of the material was retained within the closure shell, and particularly within the passageway of the chimney, with the result that when the closure was opened by outward pull applied to the tip member, in most cases a small quantity of the product spurted outwardly from the dispensing opening.
In copending U.S. patent application Ser. No. 592,007, entitled NON-SPURTING DISPENSING CLOSURE, filed June 30, 1975, by John D. McDowell, Jr. and Paul J. Nutley, now U.S. Pat. No. 3,981,421 and assigned to the Procter and Gamble Company, an anti-spurt, push-pull type dispensing closure is described. Briefly, the dispensing closure comprises a shell having a substantially cylindrical chimney and a tip mounted on the chimney and shiftable between a retracted closed position and an extended open position. The chimney is provided with angled ribs on its exterior surface and the tip is provided with cooperating lugs on its interior to provide a limited degree of relative rotation between the tip and the chimney during the shifting of the tip between its open and closed positions. It has been found that this construction prevents spurting upon opening of the closure after shaking of the contents to be dispensed.
The present invention is directed to a twist-open, anti-spurt, dispensing closure which, while not so limited in use, is particularly adapted for the dispensing of viscus or thixotropic material requiring shaking immediately prior to dispensing, such as the liquid cleaning preparations described above. The dispensing closure of the present application comprises a shell with a chimney and a tip so constructed that a limited twisting of the tip with respect to the chimney is required to shift the tip between its open and closed positions. The closure is inexpensive to manufacture in that it does not require full threads on the tip or the shell requiring the dye member forming these parts to be unscrewed therefrom. The amount of twisting required to open the closure is far less than that encountered with the conventional twist-open dispensing closures.
The dispensing closure of the present invention is reliable in operation, durable, and capable of dispensing abrasive liquids and the like. The tip may be snap-fit assembled to the shell and is captively held thereon. Finally, means may be provided to prevent removal of the shell from the container to which it is attached and additional means may be provided to render the dispensing closure child-resistant.